The agreement rate is the percentage of users who placed a card in a certain category in a card sort.

## Single card agreement rate

The single card agreement rate is the percentage of users who decided that a specific card belongs in a category. An agreement rate of 100% means that all testers agreed that a card belongs in a specific category.

### How is the agreement rate calculated?

The agreement rate is calculated using the following equation:

**(count in category * 100) / total tester count**

For instance, consider the example screenshot below:

- The card "Key lime pie" was placed in the category by all 8 of the testers. The agreement rate for that card in that category is 100% (8 * 100 / 8)
- The card "Salted caramel ice cream" was placed in the category by 7 out of 8 testers. The agreement rate for that card in that category is 87.5% (7 * 100 / 8)
- The card "Pastel de nata" was placed in the category by 3 out of 8 testers. The agreement rate for that card in that category is 37.5% (3 * 100 / 8)

## Average agreement rate

The average agreement is calculated as a simple average between the agreement rates of all cards inside a category.

In the example screenshot, the average agreement for the "Desserts" category is 75%, as that is the average of the agreement rates of all cards inside that category.

## Analysis tools

### Agreement matrix

The agreement matrix groups cards under each category based on their highest agreement rates. It gives you a visual representation of how often cards appeared in each category. Learn more

### Similarity matrix

The similarity matrix evaluates the relationship between pairs of cards. It gives you insight into which cards were most frequently grouped together. Learn more

## How many testers do I need?

In quantitative studies, the more users you can test with, the better the chance your results are accurate. As a general rule, we recommend testing with at least 20 users.

Having more testers can be particularly helpful when doing card sorting: with more testers, agreement rates become easier to interpret, and more meaningful patterns start emerging in the data.

Learn more about the ideal number of testers

## Card sorting results

To learn more about your card sorting results, check out this article: Understanding your card sorting results